Exercise monitoring system and methods

ABSTRACT

An exercise monitoring system which includes an electronic positioning device; a physiological monitor; and a display unit configured for displaying data provided by said electronic positioning device and said physiological monitor.

RELATED APPLICATIONS

The present application is a Divisional of U.S. application Ser. No.09/436,515 filed Nov. 9, 1999 now U.S. Pat. No. 6,736,759. The entiredisclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a monitoring system for use in avariety of physical activities, as well as training and analyticalmethods for physical activities. The present invention providesmonitoring systems having an electronic positioning device and/or aphysiological monitor (such as an oximeter or a heart rate monitor) inorder to provide information concerning a subject performing a physicalactivity.

2. Description of Related Art

Throughout the world, more and more people are exercising in order toimprove their general health and physical fitness. For the averageperson, however, a lack of motivation can significantly hinder theirefforts. In addition, the natural tendency is to try and achieve thegreatest results in the shortest possible time. When typicalmeasurements of physical fitness and progress such as weight loss aremonitored, however, expectations often are not met. The result can be alack of motivation, which in turn leads to a cessation of exercise.

While athletes of all ages are usually able to overcome motivationalhurdles, athletes often have difficulty in accurately measuring theirprogress. Human nature demands instantaneous feedback for motivation andencouragement. In addition, many athletes also do not know how to traineffectively for maximal improvement. For example, competitive runnersmay have difficulty determining whether their pace on a particular dayof training is too fast or too slow. While running on a track ortreadmill may allow the runner to monitor his or her speed, speed aloneis often an inadequate way to monitor optimal training levels.

Currently, there are essentially three methods of providing feedback toindividuals engaged in a physical activity. The first, competition, canprovide feedback concerning the individual's past training efforts in aparticular physical activity. Competition feedback, however, is providedlong after the training regimen has been completed, and therefore onlyallows for adjustments in subsequent training. In addition, manyindividuals are only interested in improving their general health andphysical fitness rather than competing against others.

Another method of providing feedback to an individual engaged in aphysical activity is heart rate monitoring. Heart rate monitors havebecome common place in the exercise industry and entire trainingprograms have been developed based upon the data provided by thesemonitors. Typically, an ECG-type sensor is worn by the individual (suchas in a strap which extends about the individual's chest), and heartrate (in beats per minute) is displayed on a wrist-watch type unit.While heart rate monitoring is a useful tool, heart rate data can bedifficult to interpret. In addition, many individuals often resort tostandardized tables in order to determine target heart rate trainingzones. Such standardized tables, however, only provide generalizedguidelines which may or may not be appropriate for a particularindividual or a particular physical activity.

The third feedback technique which may be used by individuals performinga physical activity is lactate monitoring. Lactate is a byproduct of theanaerobic metabolic process by which energy is produced in the body. Theamount of lactate present in an individual's bloodstream provides anindication of their level of exertion. While lactate monitoring can be avaluable tool, it requires drawing blood samples which are analyzed byan expensive, electronic device. Thus, lactate monitoring is invasive,costly, and generally only useful for experienced athletes and theircoaches.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exercise monitoring systemaccording to one embodiment of the present invention;

FIG. 2 is a schematic illustration of an exercise monitoring systemaccording to another embodiment of the present invention;

FIG. 3 depicts a human subject performing a physical activity using oneembodiment of a monitoring system of the present invention;

FIG. 4 is perspective view of the data acquisition component of themonitoring system depicted in FIG. 3;

FIG. 5 is a schematic illustration of the monitoring system depicted inFIG. 3;

FIG. 6 is an enlarged plan view of a portion of the data acquisitioncomponent of the monitoring system depicted in FIG. 3;

FIG. 7 is a view similar to FIG. 6, wherein the modules have beenremoved from the support member of the data acquisition component;

FIG. 8 is a perspective view of an oximeter module of the dataacquisition component of the monitoring system depicted in FIG. 3;

FIG. 9 is a top plan view of the display component of the exercisemonitoring system depicted in FIG. 3;

FIG. 10 is an enlarged top plan view of a portion of the display unit ofFIG. 9;

FIG. 11 is a rear plan view of a portion of the data acquisitioncomponent of FIG. 7;

FIG. 12 is a cross-sectional view of the data acquisition component ofFIG. 7, taken along the line 12—12 thereof;

FIG. 13 depicts an alternative display unit according to an embodimentof the exercise monitoring system of the present invention, wherein thedisplay unit is mounted to a handlebar of a bicycle;

FIG. 14 is a side view of the display unit of FIG. 13, wherein thebicycle handlebar is shown in cross-section;

FIG. 15 is a perspective view of an alternative embodiment of a dataacquisition component according to the present invention, wherein thedata acquisition component is configured to be worn about the chest of ahuman subject;

FIG. 16 is a plot which depicts a runner's heart rate and blood oxygenlevel as the runner's workload is progressively increased;

FIGS. 17 a and 17 b are plots depicting a runner's blood oxygen level asthe runner's pace is progressively increased;

FIG. 18 is a perspective view of an alternative embodiment of anoximeter used in a monitoring system according the present invention;and

FIG. 19 depicts an alternative display unit of a monitoring systemaccording to the present invention.

SUMMARY OF THE INVENTION

One embodiment of the present invention is an exercise monitoring systemwhich comprises:

-   -   a. an electronic positioning device;    -   b. a physiological monitor; and    -   c. a display unit (or component) configured for displaying data        provided by the electronic positioning device and the        physiological monitor.        The electronic positioning device is configured to receive        electromagnetic signals from three or more sources so that the        monitoring system can determine at least one of a subject's        location, altitude, velocity, pace, and distance traveled. In        one particular embodiment, the electronic positioning device        comprises a GPS device. The physiological monitor may be chosen        from the group consisting of: an oximeter and a heart rate        monitor.

The electronic positioning device and the physiological monitor may beprovided as part of a user-wearable data acquisition unit (or component)which is separate from the display unit. The data acquisition unit mayfurther include a support member, wherein the electronic positioningdevice and the physiological monitor are provided on the support member.In one embodiment, the electronic positioning device and thephysiological monitor are removably secured to the support member. Thedata acquisition unit may be configured to be worn by a subject in avariety of locations, such as the subject's waist or chest. The displayunit may likewise be configured in a variety of manners. For example,the display unit may be configured to be worn about a human user'swrist, or may be configured to be mounted to a bicycle (e.g., mounted tothe handlebars). The display unit may also comprise an external deviceto which the monitoring system of the present invention transmits data.For example, the monitoring system of the present invention may beconfigured to display acquired data on a personal computer (“PC”), andeven store the data on the PC for later retrieval and analysis. Themonitoring system may also be configured to display data on a treadmilldisplay screen so that the monitoring system will provide blood oxygendata for a subject walking or running on a treadmill.

The physiological monitor of the exercise monitoring system may includea probe (or sensor) configured for acquiring physiological data from auser. The probe may be incorporated into the data acquisition componentitself (such as integrally provided on or in the support member), or maycomprise a separate unit which is in electrical communication with thedata acquisition component (such as by means of a wire or cable, or bymeans of electromagnetic wave transmission). The monitoring system mayfurther include at least one audible or visual alarms which is activatedwhen data provided by at least one of the electronic positioning deviceand the physiological monitor does not meet a predetermined target(e.g., when the user's speed, blood oxygen level or heart rate exceedsor falls short of a predetermined target).

Another embodiment of the present invention is an exercise monitoringsystem which comprises:

-   -   a. an electronic positioning device configured to receive        electromagnetic signals from three or more sources so that the        monitoring system can determine a subject's velocity or pace;    -   b. a display unit configured for displaying data provided by the        electronic positioning device; and    -   c. an alarm, wherein the alarm is activated when a subject's        velocity or pace does not meet a predetermined target.        The electronic positioning device in this embodiment may        comprise a GPS device.

Yet another embodiment of the present invention is an exercisemonitoring system which comprises:

-   -   a. an oximeter configured to determine a subject's blood oxygen        level;    -   b. a display unit configured for displaying the subject's blood        oxygen level; and    -   c. an alarm, wherein the alarm is activated when the subject's        blood oxygen level does not meet a predetermined target.        By way of example, the oximeter may comprise an oximetry probe        and oximeter module, which are configured to acquire blood        oxygen data by light absorption techniques. Preferably, the        oximeters described herein are configured and positioned to        determine systemic blood oxygen levels, rather than the blood        oxygen level of targeted tissues or regions.

Another embodiment of the present invention is a method of controlling asubjects physical activity, comprising:

-   -   a. monitoring a subject's blood oxygen level while the subject        performs a physical activity; and    -   b. maintaining the blood oxygen level at a selected level while        the subject continues to perform the physical activity.        The subject may be human or animal (particularly horses, dogs,        camels, and other mammals), and the monitoring step may even        utilize the exercise monitoring systems described herein. It        should be pointed out, however that blood oxygen data may also        be acquired using conventional, readily-available oximeters.        This method of controlling a subject's physical activity may be        performed solely by the subject, or may involve another (such as        a coach or trainer). In one particular embodiment, the method of        controlling a subject's physical activity even provides a        training method for athletes and the like using blood oxygen        data.

The subject's blood oxygen level may be maintained at the selected levelby adjusting the workload of the physical activity as necessary. Infact, the exercise monitoring systems described above may even be usedfor this purpose, since embodiments of the monitoring system can beconfigured for computing and displaying the subject's workload (based onthe subject's velocity and weight, and optionally based on elevationalchanges). The subject's blood oxygen level may also be maintained at theselected level by adjusting the subject's level of exertion asnecessary. As yet another alternative, the subject's blood oxygen levelmay be maintained at the selected (or predetermined) level by adjustingthe subject's oxygen intake as necessary (e.g., by altering breathingpatterns or methods, or by restricting or expanding oxygen or airintake). In fact, by limiting oxygen intake in order to reduce thesubject's blood oxygen level athletic training (e.g., running or biking)at high altitude may be simulated.

The method of controlling a subject's physical activity is suitable fora variety of activities, including: walking, running, swimming,bicycling, skating, singing, skiing, boating, climbing, wheelchairing,snowshoeing, scuba diving, and flying. The step of monitoring bloodoxygen level may comprise:

-   -   (a) providing an oximeter, the oximeter including a probe for        non-invasively determining blood oxygen level (such as through        light absorption measurements); and    -   (b) positioning the probe on the subject at a location suitable        for detecting the subject's blood oxygen level.        Preferably, the probe is positioned such that the oximeter        determines the subject's systemic blood oxygen level. The probe        location may be chosen from the group consisting of the        subject's back (particularly the subject's lower back), head,        arm, leg, chest and torso.

It should be noted that the selected (or predetermined) blood oxygenlevel may comprise a range or a target “setpoint”. In fact, multiplepredetermined blood oxygen levels may be employed, such that thesubject's blood oxygen level is sequentially maintained at multipleselected levels (i.e., interval training). The subject's blood oxygenlevel may be maintained at each selected level:

-   -   (a) for a predetermined period of time;    -   (b) until the subject has advanced a predetermined distance        (e.g., as measured by a GPS system); or    -   (d) until the subject has performed a predetermined amount of        work (e.g., as measured by a GPS system).        Each selected (or predetermined) blood oxygen level may be        chosen on the basis of blood oxygen data previously obtained        while the subject performed a physical activity. For example,        the subject's blood oxygen level at a lactate threshold (“LT”)        may be determined. Thereafter, each selected blood oxygen level        may be chosen on the basis of the subject's LT (e.g., at LT, or        a predetermined percentage of LT). Alternatively, each selected        level may be chosen on the basis of the duration of the physical        activity. For example, the selected blood oxygen level may be        higher when the duration of the activity is greater.

In order to facilitate the method of controlling the subject'sperformance of a physical activity, an alarm may be provided. The alarmmay be configured to indicate (i.e., provide an audible and/or visibleindicia) when the subject's blood oxygen level is not at the selectedlevel (e.g., outside of a selected range, or not within a certainpercentage of a setpoint). A display unit configured for displaying thesubject's blood oxygen level may also be provided in order to facilitateperformance of the method of controlling. When the subject is a human,the display unit may be configured to display blood oxygen data to thesubject or to another (such as a coach or trainer monitoring thesubject's performance). For animal subjects, the display unit may beconfigured to display blood oxygen data to an individual such as atrainer or, in the case of horses and camels, a jockey.

It will be appreciated that the exercise monitoring systems of thepresent invention may be used for the methods of controlling a subject'sperformance of a physical activity described herein. In fact, thesubject's velocity, pace, workload, and/or distance traveled may bemeasured by an electronic positioning device provided on the exercisemonitoring system.

Still another embodiment of the present invention comprises a method ofreducing a subject's blood oxygen level variability while the subjectperforms a physical activity, comprising:

-   -   a. periodically measuring a subject's blood oxygen level while        the subject performs a physical activity; and    -   b. adjusting the manner in which the physical activity is        performed in order to reduce blood oxygen level variability.        The time variability of the subject's blood oxygen level may        also be indicated (e.g., displayed) to the subject. The time        variability of blood oxygen level may be quantified in a variety        of manners, such as the standard deviation of the subject's        blood oxygen level. The monitoring systems of the present        invention may even be configured to activate an alarm when the        time variability exceeds a predetermined level.

A method of determining a fitness indicator of a subject is alsoprovided, wherein this method comprises:

-   -   (a) recording a subject's blood oxygen level while the subject        performs a physical activity;    -   (b) varying the subject's workload (e.g., periodically        increasing workload) while continuing to record the subject's        blood oxygen level; and    -   (c) determining a fitness indicator of the subject on the basis        of the recorded blood oxygen data.

The fitness indicator may comprise, for example, the subject's lactatethreshold or VO2max (the milliliters of oxygen consumed per kilogram ofbody weight per minute). The subject's velocity (and optionallyaltitude) may be measured by a GPS device, such that the subject'sworkload may then be determined using velocity (and optionally altitude)measurements provided by the GPS device.

A method of stabilizing blood oxygen levels while exercising is alsoprovided, and comprises:

-   -   (a) monitoring the level of blood oxygen while exercising;    -   (b) adjusting breathing while continuing to exercise in order to        stabilize the level of blood oxygen.

Another embodiment of the present invention comprises a method ofcomparing a subject's physical fitness to their physical fitness on aprevious occasion, comprising:

-   -   (a) measuring an individual's blood oxygen level while the        individual performs a physical activity at a predetermined        workload, velocity or pace; and    -   (b) measuring the individual's blood oxygen level on a        subsequent occasion while the individual performs the physical        activity (particularly at the same predetermined workload,        velocity or pace).        For example, if the subject's blood oxygen level (e.g., the        subject's average blood oxygen level) is higher on a subsequent        occasion, the subject's fitness will have been improved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides an exercise monitoring system, as well astraining and analytical methods useful for subjects (both human andanimal) performing physical activities. The systems and methods of thepresent invention, for example, provide real-time data and feedbackuseful to individuals performing a physical activity (such as athletes).The monitoring system may include an electronic positioning device (suchas a GPS device) and/or a physiological monitor (such as an oximeter ora heart rate monitor).

The electronic positioning device uses electromagnetic signals fromthree or more sources in order to provide data indicative of one or moreof the subject's location, altitude, velocity, pace and/or distancetraveled. By way of example, the electronic positioning component maycomprise a GPS device which utilizes signals from satellites of theGlobal Positioning System (i.e., “GPS”) in order to provide real-timedata concerning at least one of the subject's location, altitude,heading, velocity, pace and distance traveled, and may optionallyprovide a precise time measurement.

The physiological monitor may comprise an oximeter which measures thesubject's blood oxygen level, and may also measure the subject's heartrate. Alternatively, the physiological monitor may comprise a heart ratemonitor which measures the subject's heart rate.

One embodiment of the monitoring system of the present inventionincludes both an electronic positioning device and a physiologicalmonitor (such as an oximeter or heart rate monitor) as part of anintegrated monitoring system. Such an integrated monitoring systemallows velocity, pace, and/or distance traveled information provided bythe electronic positioning device to be used in conjunction with dataprovided by the physiological monitor. In this manner, exercisingsubjects can monitor, control and/or analyze their performance whileexercising at any location (e.g., outside of a laboratory).

The present invention also provides analytical and training methodswhich utilize data provided by: (a) a physiological monitor; (b) anelectronic positioning device (such as a GPS device); or (c) thecombination of an electronic positioning device and a physiologicalmonitor (such as a heart rate monitor or an oximeter). It should bepointed out that the various analytical and training methods of thepresent invention do not require the use of the exercise monitoringsystems of the present invention. However, the exercise monitoringsystems of the present invention may be configured for implementation ofthe analytical and training methods described herein.

The monitoring systems, as well as the analytical and training methods,provided by the present invention may be used on both human and animalsubjects. Hence, the term “subject” is intended to encompass both humansand animals. By way of example, embodiments of the exercise monitoringsystems of the present invention may be used for the testing and/ortraining of horses and other animals typically involved in racing sports(including dogs and camels). Of course, these methods can also be usedin the testing and/or training of other animals not necessarily involvedin racing sports (such as rehabilitating an injured animal by puttingthe injured animal through a training program).

FIG. 1 is a schematic illustration of one embodiment of an exercisemonitoring system according to the present invention. The system of FIG.1 generally comprises an electronic positioning device 5 and aphysiological monitor 6, both of which are in electrical communicationwith a display unit 7. Electronic positioning device 5 is configured toreceive electromagnetic signals from three or more sources so that themonitoring system can determine (and display by means of display unit 5)at least one of a subject's location, altitude, heading, velocity, pace,and distance traveled. By way of example, electronic positioning device5 may be configured to receive electromagnetic signals, and processthose signals in order to determine at least one of a subject'slocation, altitude, heading, velocity, pace, and distance traveled. Thedetermined data may then be transmitted to display unit 7 for display tothe subject or other individual monitoring the subject's performance ofa physical activity. Similarly, physiological monitor 6 is configured toacquire physiological data from the subject for display by means ofdisplay unit 5. By way of example, physiological monitor 6 may beconfigured to determine one or more physiological indicia (such as thesubject's blood oxygen level or heart rate). The determinedphysiological indicia may then be transmitted to display unit 7 fordisplay to the subject or other individual monitoring the subject'sperformance of a physical activity.

FIG. 2 schematically depicts a more specific embodiment of an exercisemonitoring system according to the present invention. In the embodimentof FIG. 2, electronic positioning device 5 comprises a GPS device whichincludes a GPS antenna 80, and a GPS module 30. Physiological monitor 6comprises an oximeter which includes a probe 41, and an oximeter module40. Display unit 7 may comprise any of a variety of structuresconfigured for displaying data. For example, a simple display unit mayinclude a screen which displays the subject's speed (e.g., in miles perhour) and blood oxygen level (e.g., in terms of the percentage of oxygensaturation). The display unit may optionally be configured for linkingto (e.g., in electrical communication with) a computer 8 (such as apersonal computer of “PC”). Such linking may be provided by a cable, ininfrared link, or other means well-known to those skilled in the art. Inthis manner, data may be stored in computer 8 for later retrieval andanalysis.

An exercise monitoring system according to the present invention maycomprise a single structure, or may be subdivided into one or morecomponent structures. Thus, one embodiment of the present inventionincludes a data acquisition component and a separate data displaycomponent (i.e., display unit) which are in electrical communicationwith each other through a wired link (e.g., and electrical cable) or awireless link (e.g., via radio wave transmission). The data acquisitioncomponent may include at least one of an electronic positioning deviceand a physiological monitor, and may be configured to be worn by asubject performing a physical activity.

A variety of configurations may be provided for the data acquisitioncomponent, depending in part upon the nature of the physical activity tobe performed as well as the type of data to be acquired. For example, aphysiological monitor will often include a sensor or probe whichinteracts with the subject to acquire physiological data (such as heartrate and/or blood oxygen level). The physiological sensor or probe maybe incorporated into the data acquisition component, or may be providedas a separate unit which is in communication with the data acquisitioncomponent. For example, the physiological sensor or probe may be remotefrom the data acquisition component, yet in electrical communicationwith the data acquisition component over a wired or wireless connection(see, e.g., FIG. 18). When the sensor or probe is incorporated into thedata acquisition component itself, the data acquisition component may beconfigured to ensure proper positioning of the sensor or probe on thesubject (i.e., in a position operable to acquire the desiredphysiological data). Of course, the data acquisition component of amonitoring system according to the present invention may even comprisemultiple structures which are physically separate from each other.

The data display component may likewise be provided in a variety ofconfigurations, and its configuration may even be chosen based upon theparticular physical activity to be performed. By way of example, thedisplay component may be worn by the subject, worn by anotherindividual, attached to an apparatus associated with the physicalactivity (e.g., mounted on a bicycle) or provided as a separate,standalone unit.

FIG. 3 depicts a human subject performing a physical activity, namelyrunning, using a monitoring system according to one embodiment of thepresent invention. In the monitoring system depicted in FIG. 3, the dataacquisition component is depicted at 20, and is worn about the subject'swaist. The data display component is depicted at 7, and is worn aboutthe subject's wrist. While the system shown in FIG. 3 provides separatedata acquisition and data display components, it will be understood thatthese two components can be provided in a single structure. In addition,the configuration of data acquisition component 20 and data displaycomponent 7 in FIG. 3 is merely exemplary of one embodiment of amonitoring system according to the present invention. The structuralfeatures of the specific embodiment of the monitoring system of FIG. 3will be further described below, after the electronic configuration hasbeen described.

As mentioned previously, the data acquisition component of themonitoring system of the present invention may include an electronicpositioning device and/or a physiological monitor (such as an oximeteror a heart rate monitor). In the schematic illustration of an exemplarymonitoring system in FIG. 5, data acquisition component 20 includes bothan electronic positioning device and a physiological monitor. In theembodiment of FIG. 5, the electronic positioning device comprises a GPSdevice which may include a GPS antenna 80 and a GPS processing module30. As further detailed below, antenna 80 receives GPS satellitesignals, and signal output from antenna 80 is processed by GPSprocessing module 30 in order to provide an electrical signal whichincludes, for example, data indicative of the user's location. Data fromGPS module 30 is provided to processor/transmitter module 60 where itmay be further processed and then transmitted to display component 7over link 64.

It should be noted that the electronic positioning device used inembodiments of the monitoring system of the present invention is notlimited to a GPS device. Thus, the term electronic positioning device isintended to be inclusive of devices which receive electromagneticsignals from three or more sources, and thereafter process those signalsin order to provide data indicative at least one of the subject'slocation, altitude, heading, velocity, pace and distance traveled. Forexample, an electronic positioning device which detects radio waveand/or microwave signals from at least three sources may be used,wherein the received signals are processed in a manner similar to theprocessing of GPS signals in order to determine the subject's location,altitude, heading, velocity, pace and/or distance traveled. Even signalsfrom cellular phone towers may be employed. In addition, the term “GPSdevice” is intended to include devices which utilize signals receivedfrom satellites of the Global Positioning System developed by the UnitedStates Department of Defense, as well as systems which utilize signalsreceived from satellites of the Global Orbiting Navigation SatelliteSystem (“GLONASS”) developed by the former Soviet Union (or any othersatellite-based positioning system which receives and processeselectromagnetic signals from three or more satellites).

Data acquisition component 20 of FIG. 5 also includes a physiologicalmonitor; in this case an oximeter which may include an oximetry probe 41and an oximeter module 40. Probe 41 acquires data indicative of thesubject's blood oxygen level (and optionally heart rate), and oximetermodule 40 processes data received from probe 41 in order to provide anelectrical signal which includes data indicative of the subject's bloodoxygen level (and optionally data indicative of the subject's heartrate). Blood oxygen data from oximeter module 30 is provided toprocessor/transmitter module 60 where it may be further processed andthen transmitted to display component 7 over link 64. Data acquisitioncomponent 20 also includes a power supply 25 which provides electricalpower to GPS module 30, oximeter module 40, probe 41, andprocessor/transmitter 60, as needed. GPS antenna 80 may also receiveelectrical power from power supply 25 when an active GPS antenna isused.

It will be understood that the physiological monitor used in embodimentsof the monitoring system of the present invention is not limited to anoximeter. The physiological monitor may alternatively comprise, forexample, a heart rate monitor which may include a heart rate module andassociated sensor or probe for acquiring data indicative of thesubject's heart rate. The data acquired by a heart rate monitor sensoror probe is processed in the heart rate module in order to provide dataindicative of the subject's heart rate to processor/transmitter module60 for further processing and transmittal to display component 7 overlink 64.

Processor/transmitter module 60 may include a processor 66 whichprocesses data received from oximeter module 40 and GPS module 30 inaccordance with instructions stored in memory 67. The data is thereaftertransmitted to display component 7 by a wired or wireless link 64. Thus,electronic link 64 may merely comprise one or more electrical cables orwires located between processor 66 and display component 7 (see. e.g.,FIG. 19). Alternatively, data may be transmitted by a wireless linkusing, for example, radio waves. Thus, in the embodiment of FIG. 5,processor/transmitter module 60 includes an RF transmitter 65 whichtransmits data received from processor 66 via radio waves to receiver 76of display component 7.

As mentioned above, display component 7 includes a receiver 76 forreceiving data transmitted by data acquisition component 20. Thereceived data may include, for example, data indicative of the subject'slocation, altitude, heading, velocity, pace, distance traveled, bloodoxygen level and/or heart rate, (and optionally the current time asdetermined by the GPS device). This data is then provided to processor75 wherein it may be further processed in accordance with instructionsstored in memory 77. After processing, acquired and/or calculated datais displayed on display screen 52 where it is visible to the subject oran individual monitoring the subject's performance. Display component 7may also include a power supply 78 for supplying power to processor 75,receiver 76, and other components, as necessary, within displaycomponent 7.

It should be noted that transmitter 65 and receiver 76 may alternativelyeach comprise transceivers so that electrical signals may be transmittedin both directions (i.e., from data acquisition component 20 to displaycomponent 7, and from display component 7 to data acquisition component20).

Display component 7 may also include one or more alarms 79, each ofwhich provides an audible and/or visual alarm in response to a signalreceived from processor 75. A plurality of input devices may also beprovided on display component 7 so that the subject or other individualmay control the processing and/or display of acquired data on displayscreen 52. Such input devices may comprise, for example, input switches53–56. Display component 7 may further include a peripheral interface 85which allows display component 7 to be linked to an external device suchthat data may be transmitted from display component 7 to the externaldevice (such as a PC, as described previously). In this manner, dataconcerning the subject's performance of a physical activity may bestored for further processing, analysis and/or retrieval. Peripheralinterface 85 may be configured in a variety of manners, depending uponthe type of connection to the external device (such as a PC). Forexample, data may be transmitted from display component 7 to a PC over awired link. Thus, peripheral interface 85 may merely comprise anelectrical terminal to which one end of a cable may be attached. Theother end of the cable may then be attached to the PC, such as through aUSB port or a serial port. Alternatively, display component 7 maytransmit data by means of a wireless link, such as by radio waves orinfrared. Thus, peripheral interface 85 may also include a transmittercapable of transmitting radio waves or an infrared signal to a PC whichis configured to receive radio waves or an infrared signal. A variety ofother structures well-known to those skilled in the art may also be usedfor peripheral interface 85 in order to transmit data to a PC or otherexternal device.

Electronic Positioning Device

As mentioned above, one embodiment of the monitoring system of thepresent invention includes an electronic positioning device whichdetermines the subject's location, altitude, heading, velocity, pace,and/or distance traveled based upon electromagnetic signals receivedfrom three or more sources. While other positioning devices may beemployed, one embodiment of the monitoring system of the presentinvention employs a GPS device. In general, the GPS device receiveselectromagnetic signals from three or more satellites, and computes theuser's location based upon those signals. In essence, each satellitesignal provides the three-dimensional location of the satellite at aprecise time. The GPS device then computes the time it took for eachsignal to reach the GPS device, and this data is then used to computethe user's precise location (typically in terms of the user's longitudeand latitude at the time of receiving the GPS satellite signals, andoptionally the user's altitude).

The GPS device may generally include an antenna (an active or passiveantenna) and a GPS processing module, as previously described. Theantenna receives GPS signals from three or more orbiting satellites andtransmits the acquired data to the GPS processing module. Thus, as shownin FIG. 5 which is a schematic illustration of one embodiment of thepresent invention, GPS antenna 80 is in electrical communication withGPS processing module 30, and therefore transmits data acquired fromthree or more GPS satellites to GPS module 30. It should be noted thatwhile GPS antenna 80 and GPS module 30 are depicted as separate units,they may alternatively be combined into a single structure. GPSprocessing module 30 then computes the precise location of the subject,and may provide an electrical signal indicative of this position (e.g.,in terms of latitude, longitude, and altitude) to processor/transmittermodule 60 for further processing.

While GPS processing module 30 may merely transmit raw data indicativeof the subject's position to processor/transmitter module 60, GPS module30 may alternatively process the location data in order to compute, andprovide an electrical signal indicative of the subject's velocity,heading, pace and/or distance traveled, as well as the current time. Thecomputed data may then be transmitted to module 60 for furtherprocessing and transmittal to display component 7. Of course, it will beunderstood that, depending upon the level of processing provided by GPSmodule 30, processor/transmitter module 60 may simply receive data fromGPS module 30 and pass the data substantially unaltered to displaycomponent 7 via link 64. Thereafter, the transmitted data may be furtherprocessed within display component 7, as needed, so as to provideadditional data such as average velocity, average pace, workload (basedon the subject's weight) and/or other useful information as desired.

in order to compute the distance traveled, a “start point” must beprovided to the monitoring system. If the distance traveled is computedby GPS module 30 or processor 66 of processor/transmitter module 60, thesubject's location when data acquisition component 20 is first poweredup may be selected as the start point for purposes of calculating thedistance traveled. Alternatively, an input device may be provided ondata acquisition component 20 in order to commence calculation of thesubject's distance traveled. If transmitter 65 of processor/transmittermodule 60 is replaced by a transceiver, data acquisition component 20may also receive a start point signal from display component 7. In thismanner, the subject may input a start point (such as by pressing a startbutton or switch) provided on display component 7 in order to commencecalculation of the subject's distance traveled. As yet anotheralternative, the subject's distance traveled may be computed inprocessor 75 provided in display component 7, thus alleviating the needto provide a start point signal to data acquisition component 20.

In order to provide the above-described functionality, the GPS deviceutilized in embodiments of the present invention may employconventional, commercially-available components. As described in U.S.Pat. No. 5,627,548 which is incorporated herein by way of reference, anintegrated circuit (IC) may be used in GPS module 30, wherein the ICincludes, for example, a low-noise amplifier for boosting signalsreceived from the GPS antenna, a downconvertor for translating theamplified signals to a more suitable frequency, and one or moreprocessors (such as a code-processor and a navigation processor).Numerous manufacturers provide both GPS antennas, as well as GPS“receivers”, the latter of which may be incorporated into GPS module 30of the present invention. Commercially-available GPS receivers generallycomprise a circuit board having thereon one or more microprocessorunits, one or more custom integrated circuits, software, and otherelectronic componentry necessary for performing GPS functions. The GPSantenna (also commercially-available) is merely operatively connected tothe GPS module (such as by way of a coaxial cable, or other wired orwireless link). A power supply is also operatively connected to the GPSmodule. The GPS module will then provide (such as through a suitableelectronic connector) an electrical signal which includes dataindicative of, for example, the subject's latitude, longitude, altitude,velocity and/or heading, as well the current time (the latter based uponthe received satellite signals). Therefore, GPS module 30 may simplycomprise a commercially-available GPS receiver, along with suitableconnection elements which allow GPS antenna 80, power supply 25, andprocessor/transmitter module 60 to be operatively connected to the GPSreceiver portion of GPS module 30.

One commercially-available GPS receiver which may be used in anembodiment of the present invention is the GPS-PS1 receiver availablefrom p-blox AG, of Zurich, Switzerland. Alternatively, the GPS-MS1receiver (also available from p-blox AG) may be used. Suitable GPSantennas are also available from p-blox AG, as well as other sources.

While some commercially-available GPS systems simply display the user'slocation (typically in terms of longitude and latitude values, andoptionally altitude), as mentioned previously, an embodiment of thepresent invention utilizes GPS location data for computing velocity,pace and/or distance traveled. Thus, the GPS device used in embodimentsof the present invention may acquire location information atpredetermined intervals, such as between about 0.1 and about 1.0seconds. In this manner, the GPS device is capable of periodicallydetermining the subject's location (e.g., determining the subject'slocation between about every tenth of a second and about every second).Such periodic location data can then be further processed (such as inthe GPS module, or alternatively in processor/transmitter module 60, oreven in processor 75 of display component 7) in order to compute thesubject's velocity (e.g., speed in miles per hour), pace (e.g., theuser's speed in terms of the number of minutes to complete one mile), ordistance traveled (e.g., the distance that the user has traveled sincean initial start point). The commercially-available GPS receiversmentioned above are generally configured for computing velocity, and maybe readily programmed to compute pace and/or distance traveled. In thismanner, these commercially-available GPS receivers may be incorporatedinto GPS module 30 such that GPS module 30 will provide a signal whichincludes data indicative of the subject's latitude, longitude, altitude,velocity, heading, pace and/or distance traveled (as well as the currenttime).

An embodiment of the monitoring system of the present invention whichincludes an electronic positioning device is useful even without theinclusion of a physiological monitor. For example, an individual can usethe GPS device of the monitoring system while running (or performing anyother physical activity) in order to determine their velocity at anygiven moment (e.g., in miles per hour), their pace at any given moment(e.g., in terms of minutes per mile), and/or the total distance theyhave run since an initial start time (e.g., from the moment they beginrunning).

When the monitoring system includes both an electronic positioningdevice (such as a GPS device) and a physiological monitor (such as anoximeter or heart rate monitor), data provided by the GPS system may beused in conjunction with the physiological data for performancemonitoring, testing and/or training. By way of example, a heart ratemonitor device incorporated into a monitoring system according to thepresent invention may display a subject's heart rate at any givenmoment, while a GPS device of the system simultaneously displays thesubject's velocity and/or pace. In this manner, the subject (or anotherindividual such as a coach or trainer) can more effectively monitor thesubject's performance, exertion level and/or progress. By itself, arunner's velocity (or pace) is a poor indicator of performance and/orprogress (i.e., improvement). Likewise, heart rate alone is a poorindicator of performance and/or progress when the subject's velocity (orpace) is not known. Simultaneously monitoring velocity (or pace) andheart rate (and/or blood oxygen level), however, provides the missinglink; i.e., the physiological effect of running at a certain speed.Thus, incorporating an electronic positioning device and a physiologicalmonitor into an integrated system provides more meaningful data.

Oximeter

As blood is pumped through the lungs, deoxyhemoglobin in the bloodstreamabsorbs oxygen to become oxyhemoglobin. Thereafter, the oxygenated bloodis delivered throughout the body, where the oxygen is released in orderto support metabolic function. Medical personnel often monitor apatient's blood oxygen level as one indicator of the patient's overallcondition. For example, a patient's blood oxygen level is typicallymonitored during surgery in order to ensure that sufficient oxygen isreaching the patient's brain and other vital organs.

Blood oxygen levels are typically monitored in terms of the oxygensaturation level, which is defined as the amount of oxyhemoglobin as apercentage of the total hemoglobin. For example, the typical oxygensaturation level of a healthy adult at rest is between about 96% andabout 98%, which simply means that between about 96% and about 98% ofthe hemoglobin in the arterial blood is oxygenated (i.e., converted tooxyhemoglobin). As used herein, the term oximeter includes any devicecapable of determining blood oxygen level.

Many commercially-available oximeters employ light absorptionmeasurements to determine blood oxygen levels, as well as heart rate.When light is directed towards a volume of blood (such blood in anartery), a portion of the light is absorbed by surrounding tissue aswell as the blood. A sensor may then detect the amount of light which istransmitted through or reflected by the blood and surrounding tissue(i.e., light which is not absorbed by the blood or surrounding tissue).During systole, the volume of blood in the artery is increased, and morelight will be absorbed by the blood. During diastole, the volume ofblood in the artery decreases, and in turn the amount of lightabsorption decreases. Since light absorption by the surrounding tissueremains constant, the amount of light absorption will vary as a functionof heart rate. Therefore, the subject's heart rate can be readilydetermined simply by monitoring the amount of light absorption (e.g., bymeasuring the length of time between peak levels of light absorption).

Oxyhemoglobin and deoxyhemoglobin differ in their absorption of light,and these differences in light absorption properties can be employed todetermine the blood oxygen level. By measuring light absorption at twoor more different wavelengths, blood oxygen level can be readilydetermined. For example, deoxyhemoglobin absorbs more red light thandoes oxyhemoglobin, while oxyhemoglobin absorbs more infrared light thandeoxyhemoglobin. Since the absorption properties of oxyhemoglobin anddeoxyhemoglobin are well-known, the ratio of oxyhemoglobin to totalhemoglobin can be readily determined merely by measuring lightabsorption at a red wavelength and at an infrared wavelength. The ratioof light absorption at the two frequencies (e.g., red light absorptiondivided by infrared light absorption) can be compared to values in alook-up table in order to provide a measurement of blood oxygen level.

Typically, an oximeter directs light of two different predeterminedwavelengths in alternating fashion towards a volume of blood, and alight sensor detects light which is transmitted through or reflected bythe blood. Data acquired by the light sensor is then processed in orderto provide a measure of the oxygen level of the blood. In the embodimentdepicted schematically in FIG. 5, a probe 41 may include a pair of lightsources for directing light of two different wavelengths at a volume ofblood, as well as a light sensor for detecting light which istransmitted through or reflected by the blood. By way of example, thelight sources (such as LED's) may be configured to emit red light (e.g.,a wavelength of between about 610 nm and about 650 nm) and infraredlight (e.g., a wavelength of between about 810 nm and about 850 nm).Probe 41 is in electronic communication with oximeter module 40 via awired or wireless connection, such that probe 41 transmits dataindicative of detected light to module 40. Oximeter module 40 includes aprocessor and other electronic componentry which provides an electricalsignal indicative of the subject's blood oxygen level, and optionallythe subject's heart rate. Oximeter module 40 is in electricalcommunication with processor/transmitter module 60, such that theelectrical signal indicative of the subject's blood oxygen level (andoptionally heart rate) is transmitted to processor 66. After processing,processor/transmitter module 60 may transmit the resulting oximetry datato display component 7, as previously described. Alternatively, theoximetry data from oximeter module 40 may be merely transmitted todisplay component 7 by processor/transmitter module 60.

The oximeter device utilized in embodiments of the present invention mayemploy commercially-available components in order to provide thefunctionality described above. For example, numerous manufacturersprovide both oximeter probes, as well as oximeter modules which may beused in the present invention. Commercially-available oximeter modulesare provided, for example, as integrated circuits which may include oneor more microprocessors, software, and other electronic componentry forgenerating an electrical signal which includes data indicative of thesubject's blood oxygen level and heart rate. The oximeter probe (alsocommercially-available) is merely operatively connected to the oximetermodule (such as by way of a wired or wireless connection), and theoximeter module will then provide an electrical signal which includesdata indicative of the subject's blood oxygen level and heart rate. Acommercially-available oximeter module may be repackaged into anenclosed unit suitable for attachment to a support member (such as abelt to be worn by the subject) in electrical communication with theother elements of data acquisition component 20. Onecommercially-available oximeter module which may be used in anembodiment of the present invention is the OEM2 Pulse Oximeter Moduleavailable from Nonin Medical, Inc. of Plymouth, Minn. Suitable oximeterprobes are also available from Nonin Medical, Inc., as well as othersources.

It should be noted that the monitoring systems of the present inventionpreferably determine, and the analytical and training methods preferablyutilize, the subject's systemic blood oxygen level, rather thanlocalized oxygen levels (such as in or near active muscle tissue). Whena subject performs a physical activity, particularly a strenuousactivity, blood oxygen level within and around working muscles may varyconsiderably from the subject's systemic blood oxygen level (i.e., thelevel of oxygen in the bloodstream as a whole). Thus, the monitoringsystems according to the present invention are preferably configured inorder to minimize any localized variance in blood oxygen levels ascompared to the subject's systemic blood oxygen level. This may beaccomplished, for example, by positioning the oximetry probe in alocation of minimal muscle activity, thereby avoiding active muscletissues or regions.

Heart Rate Monitor

As mentioned previously, the physiological monitor used in certainembodiments of the present invention may comprise a heart ratemonitoring device which provides data indicative of the subject's heartrate. By way of example, oximeter module 40 in FIG. 5 may merely bereplaced by a heart rate module which processes data received from probe41 in order to provide an electrical signal which includes dataindicative of the subject's heart rate. In fact, a heart rate modulesimilar in configuration to oximeter module 40 may be employed, exceptthat the electronic componentry need not be configured for determiningthe subject's blood oxygen level. In addition, probe 41 may be used witha heart rate module, since, as described previously, the lightabsorption of blood will vary with the subject's heart rate. Duringsystole, the volume of blood in an artery increases, thereby resultingin a detectable increase in light absorption. Thus, the subject's heartrate may be readily determined, for example, by measuring the period oftime between light absorption peaks (i.e., peaks corresponding tosystole). It should be pointed out, however, that light of a single wavelength is sufficient for monitoring the subject's heart rate. Therefore,only a single light source is required in probe 41 if oximeter module 40is replaced by a heart rate module.

As an alternative to employing light absorption measurements fordetermining heart rate, electrocardiography (“ECG”) may be employed. Abeating heart produces electrical pulses which can be readily measuredin a variety of manners well-known to those skilled in the art. Forexample, a pair or electrodes may be positioned against the subject'schest in the region surrounding the heart, such that the electrodes willdetect ECG signals. Thus, probe 41 may be replaced by an ECG-type probehaving a pair of electrodes suitable for detecting ECG signals andtransmitting data indicative of the subject's heart rate to a heart ratemodule. By way of example, U.S. Pat. No. 5,491,474, which isincorporated herein by way of reference, discloses a telemetrictransmitter unit which may be used as a heart rate sensor or probe inembodiments of the present invention. The telemetric transmitter unit ofthis patent is configured to be worn about the subject's chest such thatthe electrodes of the transmitter unit are operatively positioned so asto detect ECG signals. As described in U.S. Pat. No. 5,840,039, which isalso incorporated herein by way of reference, data indicative of thesubject's heart rate may be transmitted by the telemetric transmitterunit to a telemetric receiver unit. In the present invention, thetelemetric receiver unit may simply comprise the heart rate moduleprovided by data acquisition units 20. Alternatively, data from thetelemetric transmitter unit may be transmitted directly to data displaycomponent 7 of the present invention, such as by the methods of U.S.Pat. No. 5,840,039. The transmitted heart rate data may then be furtherprocessed by data display component 7, as desired. Of course, it is alsocontemplated that instead of the wireless data transmission described inU.S. Pat. No. 5,840,039, the heart rate probe or sensor (such as thetelemetric transmitter unit described previously) may be in electricalcommunication with either data acquisition component 20 or data displaycomponent 7 by means of one or more wires.

Data Display Component

As mentioned above, display component 7 receives an electrical signalfrom data acquisition component 20 via a wired or wireless link 64 (seeFIG. 5). This electrical signal will generally include data indicativeof one or more of the following: location, altitude, velocity, pace,distance traveled, heading, blood oxygen level and heart rate. Theelectrical signal may be received, for example, by receiver 76 (whichmay alternatively comprise a transceiver). The received electricalsignal is then provided to processor 75 where the data may be furtherprocessed in accordance with instructions stored in memory 77. Theacquired data may be processed in processor 75 in a variety of manners,depending upon, for example, the type of data which the subject or otherindividual wishes to monitor. After processing, the data may then bedisplayed on display screen 52. The subject, or other individualmonitoring the subject's performance, may even select the type of datato be displayed by, for example, employing switches 53–56. By way ofexample, the subject may select one or more predetermined formats fordata display utilizing input switches 53–56.

Data display component 7 may also include one or more alarms 79 whichprovide an audible and/or visible indication to the subject or otherindividual monitoring the subject's performance. Data display component7 may be programmed such that an alarm 79 will be activated if a datavalue departs from a predetermined limit or range. For example, themonitoring system of the present invention may be programmed such thatan alarm 79 will be activated if the subject's velocity, pace, distancetraveled, blood oxygen level or heart rate is outside a predeterminedrange. In one embodiment, the subject may program the monitoring systemof the present invention, such as by using input switches 53–56, inorder to set predetermined levels or ranges for a variety of acquireddata. For example, the subject can input an alarm level or range forblood oxygen level, such that an alarm 79 will be activated if thesubject's blood oxygen level falls below the predetermined level oroutside of the predetermined range. Similar alarm set points can beestablished by the subject or another individual monitoring thesubject's performance for velocity, pace, distance traveled and/or heartrate. In this manner, the subject's performance of the physical activitycan be precisely controlled. It should be pointed out that alarms 79 maytake a variety of configurations, such as a device capable of generatingan audible sound (such as a tone or beep) in response to a signalreceived from processor 75, or a device capable of generating a visiblesignal (e.g., a blinking light source) in response to a signal receivedfrom processor 75.

As further discussed below, data display component 7 may also includeone or more status indicators 57 and 58 (see FIG. 10). Status indicators57 and 58 may be operatively connected to processor 75 such that one ofsaid status indicators is activated when data acquisition component 20is not operating properly. For example, the status indicators may merelycomprise a portion of display screen 52 which illuminates in order toalert the subject or other individual monitoring the subject'sperformance that, for example, the GPS device has not acquired thenecessary satellite signals, or the physiological monitor is notproperly acquiring physiological data from the subject.

Exemplary Embodiment of Exercise Monitoring System

As mentioned previously, FIG. 3 depicts a runner using an exemplaryexercise monitoring system according to one embodiment of the presentinvention. In the monitoring system of FIG. 3, data acquisitioncomponent 20 is configured to be worn about the waist of the subject. Asmore fully described herein, the data acquisition component can compriseany of a variety of structures and configurations, and the structureshown in FIG. 3 is merely exemplary of one embodiment of the presentinvention. The data display component in FIG. 3 comprises a data displaycomponent 7 worn about the wrist of the subject. Once again, as morefully described herein, the data display component can comprise any of avariety of structures and configurations, and that shown in FIG. 3 ismerely exemplary of one embodiment.

Data acquisition component 20 acquires data while a subject wearingcomponent 20 performs a physical activity. The acquired data isprocessed and then displayed by data display component 7. In thismanner, data may be acquired while the subject performs the physicalactivity at any location, thus allowing performance testing andmonitoring to be performed anywhere. As shown in the perspective view ofFIG. 4, data acquisition component 20 includes a support member 15 whichgenerally comprises an elongate member sized and configured to be wornabout the user's waist. Support member 15 may be made from any of avariety of suitable materials, particularly flexible materials such aspolyurethane or other plastics which can be manufactured to be bothflexible and soft. Support member 15 may include connector elements ateach end thereof in order to facilitate securing support member 15 aboutthe user's waist. These connector elements may comprise any conventionalelements used to secure a belt about a person's waist, includingconventional belt buckle elements, or hook and loop fastener elements.In the embodiment shown, male and female connector elements 21 and 22,respectively, are provided at opposite ends of support member 15.Connector elements 21 and 22 are made from a resilient plastic, therebyallowing male element 21 to be releasably snapped into female element 22in order to secure support member 15 about the user's waist. Supportmember 15 may also be adjustable in length to accommodate differentwaist sizes, and to allow support member 15 to be adjusted for comfort.

As best seen in the enlarged view of FIG. 6, the various modulesdescribed previously are mounted on support member 15 in order toprovide the desired data acquisition functions. The modules arepreferably provided on support member 15 at a side opposite to connectorelements 21 and 22 (as shown in FIG. 4). In this manner, support member15 may be worn about a subject's waist, with connector elements 21 and22 located in front, with the modules positioned adjacent the subject'slower back. Not only does this arrangement provide for ease of use(i.e., connecting and disconnecting connector elements 21 and 22), italso provides a more comfortable arrangement due to the increased bulkof the modules. In addition, when a probe or sensor (such as an oximeterprobe) is incorporated into support member 15, the probe or sensor maybe operatively positioned against the subject's lower back. Of courseother arrangements may be provided, particularly whenever it isnecessary to orient a probe or sensor at some other location withrespect to the subject's body.

GPS module 30, oximetry module 40, antenna 80 and processor/transmittermodule 60 may be provided on support member 15. Each may be removablyattached to support member 15 such that they may removed and attached asneeded, or even replaced by other modules which provide differentfunctionality (such as a heart rate monitor module). Each modulegenerally includes electronic circuitry suitable for performing thedesired data acquisition and/or processing function, as described above(e.g., acquiring data indicative of blood oxygen level of a subjectwearing support member 15).

While each module may include the necessary circuitry for independentlyacquiring, processing and transmitting data, the embodiment of dataacquisition component 20 depicted in FIG. 4 includes circuitry whichallows data and other electrical signals to be passed from one module toanother. In this manner, for example, a single processor/transmittermodule 60 may be employed for not only processing data from GPS module30 and oximeter module 40, but also for transmitting such data todisplay component 7. In addition, one or more power supplies, such asbatteries 125, may provide power to multiple modules provided on supportmember 15. In order to provide such electrical integration of dataacquisition component 20 and the various modules attached thereto,support member 15 may include a plurality of electrical conduits toallow electrical signals to be exchanged between the various modules, asdesired. Each of the modules (including antenna 80) is configured suchthat each may be attached to belt 20 in electrical communication withone or more of the electrical conduits of belt 20.

Electrical conduits may be provided on support member 15 in a variety ofmanners, such as along inner surface 24 or outer surface 23 of supportmember 15. Alternatively, a plurality of electrical conduits may beprovided within the interior of support member 15. As best seen in thecross-sectional view of FIG. 12, a plurality of electrical conduits 63extend through the interior of support member 15, and are thus protectedand insulated by the material from which support member 15 is formed.Individual conduits may be provided within support member 15 (as shownin FIG. 12), or a flexible electrical strip such as a membrane circuitmay be provided within support member 15. One or more separate conduitsfor transmitting electrical power may also be provided in support member15. Thus, as seen in FIG. 12, first and second power cables 61 and 62,respectively, extend through the interior of support member 15.Electrical conduits 63 and power cables 61 and 62 may extend through theinterior of support member 15 in any of a variety of patterns; generallyas necessary to provide the desired electrical connections between thevarious modules and power supplies. Of course, it will be understoodthat conduits for transmitting electrical power from batteries 25 to thevarious modules may also be provided on a flexible electrical stripalong with the electrical conduits described previously.

The various modules and support member 15 are configured such that eachmodule may be attached to support member 15 in electrical communicationwith one or more of electrical conduits 63, and optionally one or bothof power cables 61 and 62. As best seen in the top plan view of FIG. 7,wherein the modules have been removed from support member 15, aplurality of electrical apertures 29 (also commonly referred to asfemale connectors or female electrical terminals) are provided onsupport member 15. Electrical apertures 29 may be arranged in anydesired pattern, and the rectangular grid shown is merely exemplary ofone possible arrangement. The arrangement of electrical apertures 29,however, should correspond with the arrangement of electrical connectorsprovided on each module (as described below). Each aperture 29 is inelectrical communication with one of electrical conduits 63. A pair ofpower apertures 28 are also provided above and below each grid ofelectrical apertures 28, and each power apertures is in electricalcommunication with one of first and second power cables 61 and 62.

Turning to FIG. 8 which depicts GPS module 30, a plurality of electricalconnectors 33 (also commonly referred to as male connectors or maleelectrical terminals) extend away from rear surface 34 of GPS module 30.Electrical connectors 33 may be arranged in the same pattern aselectrical apertures 29 on support member 15. Similarly, GPS module 30includes a pair of power connectors 32 which extend away from rearsurface 34 of module 30, above and below the grid of electricalconnectors 33. In this manner, GPS module 30 may be attached to supportmember 15, with each electrical connector 33 engaging an electricalaperture 29 on support member 15 and each power connector 32 engaging apower aperture 28 on support member 15. Thus, the arrangement ofelectrical connectors 33 and power connectors 32 on GPS module 30 shouldcorrespond to an arrangement of electrical apertures 29 and powerapertures 28 on support member 15. In the embodiment of FIG. 7, eachrectangular grid of electrical apertures 28 and corresponding pair ofpower apertures 28 (i.e., above and below the rectangular grid) areidentical. Thus, GPS module 30 can be attached to support member 15 at avariety of locations. The other modules may have an arrangement ofelectrical connectors 33 and power connectors 32 which is similar tothat for GPS module 30 (as shown in FIG. 8). In this manner, each modulecan be attached to support member 15 at a variety of locations.Alternatively, each module may have a unique configuration which allowsthat module to be attached to support member 15 only at one or moreselected locations.

In order to further secure GPS module 30 to support member 15, a pair ofmounting tabs 31 may also extend away from rear surface 34 of module 30.A pair of corresponding mounting apertures 27 are provided on supportmember 15. Mounting tabs 31 and mounting apertures 27 are arranged suchthat GPS module 30 may be attached to support member 15 with eachmounting tab 31 engaging a mounting aperture 27 on support member 15.Each mounting tab 31 may be resilient in nature such that the endportion of the mounting tab will engage a mounting aperture, therebysecurely attaching GPS module 30 to support member 15. The other modulesmay each include similar mounting tabs such each module may be securelyattached to support member 15 in the same manner. In fact, each modulemay have a shape and configuration similar (or even identical to) GPSmodule 30. Of course a variety of alternate configurations may beemployed for each module, particularly if the system is designed suchthat each module can be attached to support member 15 only at a single,predetermined location. It should be pointed out thatprocessor/transmitter module 60 of the embodiment shown in FIG. 4 issized somewhat larger than GPS module 30 and oximeter module 40. Thus,module 60 may include four mounting tabs 31 for attachment to supportmember 15 at region P shown in FIG. 7.

While individual power supplies may be provided in each module, one ormore power supplies may be provided on support member 15 in order toprovide electrical power to each module. A variety of sources ofelectrical power may be provided, such as rechargeable ornon-rechargeable batteries, one or more solar cells, or a combination ofany of the foregoing power sources. In the embodiment shown in FIG. 4, apair of batteries 125 are provided on support member 15 in electricalcommunication with first and second power cables 61 and 62. Each battery125 may be removably or permanently secured to support member 15, andmay be located internally or externally of support member 15. Eachbattery 125 may provide power to selected modules, or both batteries maybe configured to provide power to all of the modules. A power switch 26may also be provided on support member 15. Power switch 26 is operablefor turning support member 15 on and off (i.e., allowing power to besupplied to the modules when switch 26 is in its on position).

FIG. 15 depicts an alternative data acquisition component according toan embodiment of the present invention. In the embodiment of FIG. 15,the data acquisition component is configured similar to a bra, andtherefore includes a fabric article 114 configured to be worn about asubject's chest. A support member 115 is incorporated into the fabricarticle. In fact, support member 115 may be configured identical tosupport member 15 described above, and includes the various modules andother components described in conjunction with the data acquisitioncomponent of FIG. 4. Support member 115 may be secured to fabric article114 in a variety of manners, such as an adhesive or by sewing supportmember 115 directly to fabric article 114. An opening may also beprovided in fabric article 114 in the region of the oximeter probe inorder to allow the probe to be urged against the subject's back, such asbelow the subject's shoulder blade. Of course it will be recognized thatsupport member 115 may be used without fabric article 114, such thatsupport member 115 is merely secured about the subject's chest similarto the manner in which the telemetric transmitter unit of a conventionalheart rate monitor is secured about a user's chest.

As best seen in FIGS. 11 and 12, probe 41 is integrally provided onsupport member 15 such that probe 41 extends partially away from innersurface 24 of support member 15. In this manner, support member 15 willurge probe 41 against the subject's skin in the lower back region inorder to acquire blood oxygen data. An electrical connector 45 (such asa cable or wire) electrically connects probe 41 to the oximeter module.Probe 41 includes a first light source 42 configured for emitting redvisible light, and a second light source 43 configured for emittinginfrared light. First and second light sources 42 and 43 may comprise,for example, LED's. Probe 41 also includes a light sensor 44. Thus,probe 41 may acquire blood oxygen and heart rate data in the mannerdescribed previously.

FIG. 18 depicts an alternative embodiment of a physiological monitor foruse with the data acquisition component of the monitoring system of thepresent invention. In the embodiment of FIG. 18, probe 141 is remotefrom the support member for the data acquisition component of themonitoring system. Thus, probe 141 is operatively connected to oximetermodule 130 by means of a cable 145. Of course another suitable wired orwireless link may be used in place of cable 145. The configuration ofFIG. 18 is advantageous in that probe 141 may be attached to the subjectin a variety of locations, such as the subject's lower back, torso,beneath the shoulder blade, or even on the subject's head (such as onthe subject's forehead). Therefore, probe 141 may be positioned in avariety of locations. The embodiment of FIG. 18 is also advantageouswhen the monitoring system is used on a non-human subject such as ahorse. Probe 141 may be attached to the horse's forehead (such as usingadhesive or a suitable harness), while a jockey or trainer riding thehorse wears data acquisition component 20 (such as around their waist).

Display Component

As discussed previously, particularly in conjunction with thedescription of the schematic illustration of FIG. 5, the monitoringsystem of the present invention includes a display component (or displayunit) for displaying data which has been acquired and processed by thedata acquisition component. The display component of the monitoringsystem of the present invention may comprise any of a variety ofstructures suitable for displaying data and other information to thesubject or an individual monitoring the subject's physical activity(such as a trainer or a coach). The display component may thereforecomprise a personal computer having a monitor associated therewith,wherein the personal computer receives data from the data acquisitioncomponent via a wired or wireless connection. Alternatively, the displaycomponent may comprise a display device which is configured for use in aparticular physical activity, such as a display unit which attaches to abicycle in a location visible to the rider (e.g. a handlebar-mounteddisplay unit).

The display component may alternatively comprise a “heads-up” typedisplay unit configured for displaying data and other informationdirectly to the subject. As used herein, the term “heads-up displayunit” refers to any display device which is configured to display datato the subject in front of the subject's face. Such a device may beconfigured to project data and other information onto glasses worn bythe subject, swimming goggles, a visor worn by the subject (such as avisor attached to a bicycle helmet), or even onto a display screen whichis physically attached to helmet, visor, hat or other structurepositioned on the subject's head in a position so that data and otherinformation displayed thereon is directly visible to the subject. FIG.19 depicts an exemplary heads-up display unit 107 comprising glasses ofthe type described in patent application number WO 99/23524 (which isincorporated herein by way of reference). Such glasses include a displayassembly 153 which displays data onto eyeglass lens 152. A cable (orwire) 154 connects the glasses to processor/transmitter module 60,through peripheral interface 68 provided on module 60. Such a displaydevice is available from the MicroOptical Corporation of Boston, Mass.Alternatively, the display device described in patent application numberWO 99/23525 (which is incorporated herein by way of reference) may beused. The display device described in this latter patent applicationessentially provides a display screen positioned in front of thesubject's eyeglasses (or is otherwise positioned in front of thesubject's face) so that the subject may view data and other informationprovided on the display screen while still being able to see through theglasses. The focal point of the display screen, however, may be adjustedso as to appear several feet in front of the subject's glasses. In thismanner, the subject may view the data and other information provided onthe display screen, while still being able to use the glasses in anormal fashion. Other suitable heads-up type display devices arewell-known to those skilled in the art, and may be utilized in themonitoring system of the present invention.

FIGS. 9 and 10 depict yet an exemplary display component 7 according toone embodiment of the present invention. Display component 7 comprises awrist watch-type display unit which may be worn about the subject'swrist. Display unit 7 includes a flexible band 51 by which the displaycomponent may be secured about a subject's wrist. Display component 7also includes a display screen 52, which may be configured similar tothe display screen of a digital wrist watch. Thus, display screen 52 isconfigured so as to display data and other information to the subject bymeans of an LCD screen, or other suitable means well-known to thoseskilled in the art. Display component 7 further includes actuators orswitches 53–56 which allow the subject to operate and control themonitoring system of the present invention. Display screen 52 also maybe subdivided into a number of regions which are configured to displayspecific information to the subject. For example, first display region70 may be configured as a three digit display which provides thesubject's blood oxygen level (as a percentage of saturation) or thesubject's heart rate (in beats per minute). Second display region 71 issimilarly configured as a three digit display, which may be used todisplay the subject's velocity (in miles per hour or kilometers perhour) or the subject's pace (e.g., in minutes per mile). A third displayregion 72 is also shown, and may be configured to display, for example,elapsed time.

Display screen 52 also includes first and second status indicators 57and 58. Status indicators 57 and 58 may be configured such that statusindicator 57 will illuminate when the GPS device has acquired thenecessary satellite signals for measurement purposes. Second statusindicator 58 may similarly illuminate when the sensor or probe for thephysiological monitor (such as an oximeter or heart rate monitor) isoperable and acquiring physiological data from the subject. First andsecond mode indicator 73 and 74 may also be provided on display screen52. First mode indicator 73 merely indicates to the subject the currentmode of operation of display component 7. During use, the subject mayalter the mode of operation of display component 7 in order to alter theparticular data or other information displayed on display screen 52. Thesubject may utilize mode switch 54 to toggle display screen 52 so as todisplay one or more of the following data: blood oxygen level, heartrate, elapsed time (“TM”), average speed, maximum speed, year-to-datemiles or kilometers (“YTD”), or the current time (“clock mode” or “CL”).Second mode indicator 74 merely indicates to the subject whether or notdata is being displayed in terms of miles per hour, kilometers per hour,or minutes per mile.

In order to operate display component 7, a number of actuators orswitches are provided. Thus, as mentioned above, mode switch 54 is usedto toggle display screen 52 between various modes of operation.Start/stop switch 53 may be used to commence data measurement. Forexample, the subject may press start/stop switch 53 when they beginperforming a physical activity such that the measurement of elapsed timeand distance traveled will begin at that point. When the start/stopswitch 53 is depressed a second time, measurement of elapsed time anddistance traveled will stop, similar to the manner in which achronograph is employed. Display component 7 also includes third andfourth actuators 55 and 56 positioned on either side of display screen52. Actuators 55 and 56 may be used for a variety of purposes, dependingupon the configuration of the monitoring system. For example, actuator55 may be used to toggle first display region 70 between displayingblood oxygen level and heart rate. Similarly, actuator 56 may be used totoggle second display region 71 between displaying miles per hour,kilometers per hour, or minutes per mile.

FIGS. 13 and 14 depict an alternative display unit 107 which isconfigured to be mounted on a bicycle such that a subject riding thebicycle can view the data displayed on display unit 107. Display unit107 includes a main housing 151 and a clamp member 160 positionedbeneath main housing 151. Main housing 151 and clamp member 160 eachinclude a semi-circular groove such that when main housing 151 and clampmember 160 are positioned as shown in FIG. 14, a circular opening isprovided therebetween. This circular opening is sized an configured toaccept a handlebar 185 of a bicycle. In this manner, when clamp member160 is secured to main housing 151 (such as by means of screws 161),handlebar 185 is securely held between clamp member 160 and main housing151 as shown.

Display unit 107 further includes a display screen 152 which may beconfigured in the same manner as display screen 52 of the display unitshown in FIG. 10. Display unit 107 also includes input switches 15–156,which may be configured in the same manner as input switches 53–56 onthe display unit shown in FIG. 10. Thus, display unit 107 is essentiallythe same as display unit 7 of FIG. 10, except that the clampingmechanism described above has replaced band 51, of the display unitshown in FIG. 7. It should be noted that band 51 of display unit 7 ofFIG. 10 may also be used to secure display unit 7 to the handlebars of abicycle, particular if band 51 employs a hook and loop fastening system.

Analytical and Training Methods

While the monitoring system of the present invention may simply displaythe exercising subject's location (e.g., in terms of longitude andlatitude), altitude, velocity, pace, heart rate (e.g., in beats perminute), distance traveled, and/or blood oxygen level (e.g., as apercentage of saturation), the monitoring system of the presentinvention may be configured to further process, analyze or otherwiseutilize this data. In this manner, the monitoring systems of the presentinvention may be used to monitor, analyze and/or control a subject'sperformance of a physical activity at any location.

By way of example, runners are very interested in monitoring theirvelocity, pace and/or total distance run. A simple pedometer may providea rough estimate of the total distance run, however, such devices areinaccurate and do not provide a direct measurement of velocity or pace.While treadmills typically provide an accurate measurement of velocity,pace and total distance, many runners prefer outdoor running. Running ona track or premeasured route will also provide a measure of totaldistance run, however, many runners do not want to be restricted torunning round and round on a track or on the same course day after day.In addition, the runner will be unable to determine their instantaneousvelocity, pace or total distance traveled.

In order to overcome the above problems, the monitoring systems of thepresent invention which include a GPS device may be configured toprovide more than just location information. As described previously,the location data acquired by the GPS device may be used to compute anddisplay the subject's velocity, pace and/or distance traveled. Suchinformation is particularly useful when the subject is performing aphysical activity wherein performance may be measured in terms of speed,time and/or distance, such as walking, running, swimming, wheelchairing(e.g., wheel chair racing), bicycling, skating (e.g., speed skating onany surface), skiing (e.g., cross-country skiing), or boating (e.g.,rowing, sailing, kayaking, or canoeing), or climbing (e.g., rockclimbing). When the system is worn by a human subject performing aphysical activity, he or she may simply view the display screen at anytime in order to obtain their speed, pace and/or distance traveled.Alternatively, particularly when the subject is an animal such as ahorse, the display screen may be viewed by another individual (such as atrainer or even a jockey) in order to monitor the animal's speed, paceand/or distance traveled.

A monitoring system according to one embodiment of the present inventionmay also be configured (e.g., programmed) to provide a visual and/oraudible alarm which is responsive to data provided by the GPS deviceand/or a physiological monitor (when provided). In one embodiment, thesystem is user-programmable so that a visible and/or audible alarm isactivated when at least one of the subject's speed, pace, blood oxygenlevel and heart rate departs from a predetermined target, and/or whenthe subject has traveled a predetermined target distance. For example, arunner may input a predetermined pace of 6:00 per mile (a pace “setpoint”). Thereafter, the system alarm will activate whenever therunner's pace departs from the desired 6:00 per mile pace by more than acertain amount (e.g., ±10%). The alarm will remain activated until therunner's pace returns to the desired level. The runner may also input apredetermined distance. Thereafter, the system alarm will activate whenthe runner has traveled this predetermined distance. In this manner, therunner can precisely control their speed and/or total distance withouthaving to run on a treadmill or track.

The monitoring system may also be configured such that multiple targets(or set points) may be established by a user (e.g., the subjectperforming the physical activity, or a coach or trainer). For example, arunner may wish to perform interval training wherein they maintain afirst predetermined pace for a first predetermined period of time ordistance, and thereafter maintain a second predetermined pace for asecond predetermined period of time or distance. Thus, the monitoringsystem of the present invention may be configured to allow for the inputof multiple setpoints (or targets) and multiple time or distanceintervals. Thereafter, a system alarm will activate when the runner'space departs from a specified setpoint of a particular interval, therebyallowing the runner to perform interval training at precise speedsand/or distances.

The systems of the present invention may also be configured forrecording speed, pace and/or distance traveled data, and maintainingsuch data in memory for later retrieval and/or display. For example, thestart button (or other input device) may be activated in order tocommence recording of data (such as to coincide with beginningperformance of the physical activity). The stop button (or other inputdevice) may thereafter be activated upon completion of the physicalactivity. Speed, pace, average speed, average pace, elapsed time and/ordistance traveled data may then be retrieved from memory and displayed.

When the system of the present invention includes both a GPS device anda physiological monitor, data provided by the GPS device may be used inconjunction with data provided by the physiological monitor. While heartrate and blood oxygen data is useful, the utility of such data isgreatly improved if the subject's workload is also known. Thus,embodiments of the monitoring system of the present invention whichincludes both a GPS device and a physiological monitor allow for themonitoring of a physiological parameter (e.g., heart rate or bloodoxygen level) and workload. A user may even input their weight so thatthe monitoring system may compute real-time workload based upon thesubject's velocity and altitude changes. In this manner, the system evenaccounts for elevational changes when determining (and even displaying)the subject's workload. Thus, meaningful data can be obtained even whenthe subject is exercising at varying altitudes (e.g., running or bikingon hilly terrain).

Applicants have also found that monitoring blood oxygen levels whileperforming a physical activity provides data which is useful for bothtraining and analytical purposes. For example, applicants believe thatblood oxygen data provides an indicia of metabolic function, andtherefore provides an effective training parameter which can replace orbe used in conjunction with heart rate monitoring. As further describedbelow, blood oxygen monitoring also allows for training and analyticaltechniques which are generally difficult to implement using conventionalphysiological monitoring such as heart rate monitoring.

As an individual performs a physical activity, the working musclesconsume oxygen at a rate which is higher than the rate of oxygenconsumption while at rest. The body compensates for the increased oxygenrequirements by increasing oxygen intake and/or blood flow. Oxygenintake may be increased, for example, by increasing breathing rateand/or the volume of air inhaled in each breath, while blood flow isincreased by an increase in heart rate. At low levels of physicalexertion, the blood oxygen level will remain at or near the subject'snormal resting level. At these low levels of exertion, energy isprimarily provided by an aerobic metabolic process which consumesoxygen. Since the cardiovascular system is able to supply sufficientoxygen to meet the body's demands, blood oxygen level remains at or nearthe normal resting levels.

As the level of exertion is increased, however, the cardiovascularsystem is unable to supply sufficient oxygen to meet the demands ofworking muscles. Thus, the body will begin to supply a portion of theenergy requirements by an anaerobic metabolic process which does notconsume oxygen. However, lactic acid is a byproduct of the anaerobicprocess, and must be eliminated by the body in order to prevent musclefailure. When only a small portion of the subject's energy requirementsare provided by the anaerobic process, the body is generally able toeliminate the lactic acid byproduct. As the level of exertion isincreased, however, the anaerobic process is responsible for more andmore of the body's energy requirements. Eventually, the body is unableto eliminate lactic acid at the same rate that it is being produced. Atthis point (often referred to as the “lactate threshold” or “LT”),lactic acid will begin to accumulate in the working muscles, eventuallyleading to muscle failure. If the subject continues to perform at alevel of exertion above LT, it is only a matter of time until theworking muscles begin to fail and the subject must stop.

Applicants have surprisingly found that blood oxygen data provides anindirect measurement of the body's metabolic functioning. For example,as the level of exertion is progressively increased, the blood oxygenlevel will decrease. The plot shown in FIG. 16 depicts a runner's heartrate and blood oxygen level as their workload is progressivelyincreased. Workload can easily be computed on the basis of the subject'sweight and speed (and optionally altitude changes if running on a hillycourse), and the monitoring system of the present invention can readilycompute and display the subject's workload. As noted from the plot FIG.16, heart rate increases with workload, while blood oxygen leveldecreases. Thus, it is apparent that blood oxygen level (particularlysystemic blood oxygen level) varies with the metabolic functioning ofthe body. In fact, Applicants' discovery that blood oxygen levelprovides an indicator of metabolic function is quite useful in thatblood oxygen data can now be used to monitor, analyze and/or control asubject's performance of a physical activity. Thus, the presentinvention provides methods using blood oxygen data to perform one ormore of these functions. In fact, embodiments of the monitoring systemof the present invention may be configured (e.g., programmed) to provideone or more of these functions (such as activating an alarm when thesubject's blood oxygen level departs from a predetermined target levelor range). It should be pointed out, however, that the methods of thepresent invention which utilize blood oxygen data need not be performedusing the exercise monitoring systems of the present invention.

One particular method provided by the present invention is a method ofcontrolling (i.e., regulating) a subject's physical activity bymonitoring the subject's blood oxygen level, and maintaining thesubject's blood oxygen level at a selected level (such as a setpoint ora range) while the subject continues to perform the physical activity.Such a method can provide an effective training tool for athletes inthat they (or their coaches) can more effectively control trainingsessions, or even monitor their performance during a race. For example,if a marathoner knows their appropriate blood oxygen level forcompleting a marathon, they can monitor their blood oxygen level duringthe race in order to ensure that their blood oxygen level does notexceed or fall below their target level.

The subject's blood oxygen level can be maintained at a selected levelby adjusting the subject's workload (e.g., slowing down, speeding up,changing gears on a bike, etc.). Similarly, the subject's level ofexertion may also be modified as needed in order to maintain their bloodoxygen level at the selected level. The subject's oxygen intake may evenbe modified in order to maintain blood oxygen at the selected level. Forexample, various devices are available for regulating the amount ofoxygen which is inhaled by an exercising subject (such as by restrictingair flow to the user's lungs). A swimmer can also regulate their oxygenintake by regulating their breathing. Thus, a swimmer can even use themonitoring systems of the present invention (particularly an embodimenthaving an audible alarm which activates when blood oxygen departs fromthe selected level) to regulate their blood oxygen by altering breathingpatterns. A subject can also control the depth or volume of theirbreathing (e.g., deep or shallow breathing) in order to maintain bloodoxygen at the desired level. The subject's blood oxygen level can alsobe maintained at a plurality of selected levels for one or morepredetermined intervals. Thus, interval training can be performed basedupon blood oxygen data.

The subject may also perform initial testing in order to determinedesirable blood oxygen levels or heart rate for subsequent training orcompetition. For example, the subject may perform a test routine whichestimates the subject's lactate threshold (i.e., the subject's bloodoxygen level or heart rate at their lactate threshold). Thereafter, thesubject may perform a physical activity at a blood oxygen level which isselected on the basis of their previously determined lactate threshold(“LT”). By way of example, the subject's LT may be determined using aplot similar to that of FIG. 16. The subject performs a physicalactivity while their blood oxygen level is monitored. The subject'sworkload (e.g., speed) is then incrementally increased at predeterminedintervals (e.g., increase speed by 1% every two minutes) untilexhaustion (or some other selected endpoint). When blood oxygen isplotted against workload (or even speed), the subject's LT willgenerally correspond to the point of inflection identified at A in FIG.16.

As yet another alternative, a fitness parameter (such as LT) of asubject may first be determined. Thereafter, the same fitness parametermay be measured on subsequent occasions in order to measure improvementsin the subject's fitness.

The monitoring system of the present invention described above may evenbe programmed to provide for determining a fitness indicator (such asLT). The subject's weight may be inputted into the system, and thesubject will then begin performing the physical activity (e.g.,running). The system may determine the subject's speed and altitudechanges, which the system then uses to calculate the subject's workload.The system may even be programmed to signal to the subject when theworkload should be increased (such as by activating an alarm). Once thetest protocol has been completed, the system will calculate thesubject's LT (or other fitness indicator) on the basis of the acquiredworkload and blood oxygen data. Alternatively, the system may use heartrate (rather than blood oxygen data) to compute the fitness indicator(such as LT) by well-known methods. One such well-known test protocol isthe Conconi Test which employs heart rate measurements with increasingworkload to determine a subject's VO2max.

Blood oxygen data can also be monitored while a subject performs aphysical activity in order to reduce variability in blood oxygen levels.By stabilizing blood oxygen levels while performing at a constantworkload, the subject's performance will be improved. Thus, themonitoring system of the present invention may be configured to measurethe time variability of the subject's blood oxygen level, particularlywhen the workload remains at a substantially constant level. The timevariability may simply be calculated as the standard deviation of bloodoxygen over a predetermined time interval (e.g., the standard deviationof blood oxygen level over the preceding 5 seconds). The manner in whichthe physical activity is performed may then be adjusted in order toreduce the time variability of blood oxygen level. In fact, the systemmay even be configured to activate an alarm if the time variability ofthe subject's blood oxygen level exceeds a predetermined limit. By wayof example, the subject may reduce the time variability of blood oxygenby stabilizing their breathing (e.g., concentrating on deep, rhythmicbreathing), or by merely concentrating on stabilizing their workload orlevel of exertion.

By way of example, the plot of FIG. 17 a depicts a runner's blood oxygenlevel as their pace (in miles per hour) is gradually increased. It willbe noted that the subject's blood oxygen level shows significantvariability which does not correlate with increases in workload. Inother words, the subject's blood oxygen level shows significant peaksand valleys, rather than gradually decreasing as would be expected. Whenblood oxygen level drops and rises rapidly, the subject's performancewill suffer. For example, lactate levels may begin to rise, leading topremature muscle failure. FIG. 17 b is a plot from the same runner,however the runner concentrated on their breathing (i.e., rhythmic, deepbreathing from their belly, rather than from their chest). The result isthat blood oxygen levels are more stable, even though the workload isincreasing. In fact, the subject's blood oxygen level in FIG. 17 bremained substantially constant at about 96% when pace was increasedfrom about 6 mph to about 9 mph. In the plot of FIG. 17 a, however, thesubject's blood oxygen level varied between about 91% and about 98% overthis same pace range. Such variability in blood oxygen level willinevitably lead to decreased performance.

1. A method of controlling a subjects physical activity, comprising: (a)monitoring a subject's blood oxygen level while the subject performs aphysical activity; and (b) maintaining said blood oxygen level at aselected level while the subject continues to perform said physicalactivity.
 2. The method of claim 1, wherein said blood oxygen level ismaintained at said selected level by adjusting the workload of saidphysical activity as necessary.
 3. The method of claim 1, wherein saidblood oxygen level is maintained at said selected level by adjusting thesubject's level of exertion as necessary.
 4. The method of claim 1,wherein said blood oxygen level is maintained at said selected level byadjusting the subject's oxygen intake as necessary.
 5. The method ofclaim 1, wherein said physical activity is chosen from the groupconsisting of: walking, running, swimming, bicycling, skating, singing,skiing, boating, climbing, wheelchairing, snowshoeing, scuba diving, andflying.
 6. The method of claim 1, wherein said step of monitoring bloodoxygen level comprises: (a) providing an oximeter, said oximeterincluding a probe for non-invasively determining blood oxygen level; and(b) positioning said probe on said subject at a location suitable fordetecting the subject's blood oxygen level.
 7. The method of claim 6,wherein said probe is positioned such that said oximeter determines thesubject's systemic blood oxygen level.
 8. The method of claim 4, whereinsaid blood oxygen level is maintained at each selected level: (a) for apredetermined period of time; (b) until the subject has advanced apredetermined distance; or (c) until the subject has performed apredetermined amount of work.
 9. The method of claim 1, wherein saidselected level is chosen on the basis of blood oxygen data previouslyobtained while said subject performed a physical activity.
 10. Themethod of claim 1, wherein said selected level is chosen on the basis ofsaid subject's lactate threshold.
 11. The method of claim 1, whereinsaid selected level is chosen on the basis of the duration of saidphysical activity.
 12. The method of claim 1, further comprising thestep of providing an alarm, said alarm configured for indicating whenthe subject's blood oxygen level is not at said selected level.
 13. Themethod of claim 1, further comprising the step of providing a displayunit configured for displaying the subject's blood oxygen level.
 14. Themethod of claim 13, wherein said subject comprises a human, and saiddisplay unit is positioned so that the blood oxygen level displayed bysaid display unit can be viewed by said subject.
 15. The method of claim14, wherein said physical activity comprises bicycling, and said displayunit is attached to the subject's bicycle so as to be visible to thesubject.
 16. The method of claim 1, further comprising the step ofmeasuring at least one of the subject's velocity, pace, or distancetraveled.
 17. The method of claim 16, wherein said measuring stepcomprises: providing a GPS device operable for measuring at least one ofthe subject's velocity, pace or distance traveled.
 18. The method ofclaim 16, further comprising the step of providing a display unitconfigured for displaying the subject's blood oxygen level, and at leastone of the subject's velocity, pace or distance traveled.
 19. A methodof reducing a subject's blood oxygen level variability while the subjectperforms a physical activity, comprising: (a) periodically measuring asubject's blood oxygen level while said subject performs a physicalactivity; and (b) adjusting the manner in which said physical activityis performed in order to reduce blood oxygen level variability.
 20. Amethod of determining a fitness indicator of a subject, comprising: (a)recording a subject's blood oxygen level while the subject performs aphysical activity; (b) varying the subject's workload while continuingto record the subject's blood oxygen level; and (c) determining afitness indicator of said subject on the basis of the recorded bloodoxygen data.